Qtableview verticalheader show icon instead of numbers

advseo32

i have implemented the functions but the programme crashed

her is my header file @#include <QSortFilterProxyModel>
#include <QItemSelectionModel>
class MytableModel : public QSortFilterProxyModel
{
public:
explicit MytableModel(QObject parent = 0);
QVariant headerData(int section, Qt::Orientation orientation, int role) const;
QVariant data(const QModelIndex &proxyIndex, int role) const;
void SetSelectionModel(QItemSelectionModel selection) ;
private:
QItemSelectionModel *m_selectionModel;

};
@

myfunction her :
@
void MytableModel::SetSelectionModel(QItemSelectionModel* selection)
{
m_selectionModel = selection ;
}
@

her is my main

@
// my main model venteModel
// my proxy model ProxyProduitModel
// my view listProduitTableView

ProxyProduitModel->SetSelectionModel(listProduitTableView->selectionModel());
venteModel->setQuery("select *from Produit");
ProxyProduitModel->setSourceModel(venteModel);
listProduitTableView->setModel(ProxyProduitModel);

@

andre

You'll have to do better than "it crashes". Fire up your debugger when that happens, and figure out what is going wrong from that.

advseo32

i'm not familiare with debugger but, i have try to figure out ,what's the problem, and i get the line where the problem is happned

this @
// Her i get the index(0,0) from proxymodel
QModelIndex index = this->index(0,0) ;
// then i have maked the test

if( orientation == Qt::Vertical)
     if( orientation == Qt::Vertical && Qt::DecorationRole )
      // her is the line , the programme crashes her

if(m_selectionModel->isRowSelected(index.row(),index)) ;
return QPixmap("imgs/arrow.png");@

advseo32

Now, the problem is in the index of selected row

i try to get then selected index in view like so, but isn't works
@proxyModel->sourceModel()->index(0,0) ;@
or @proxyModel->index(0,0) ;@

i want to know how i get the selected row index, to be able to use it in

@isRowSelected(int row, const QModelIndex & parent)
and
isSelected(const QModelIndex & index)
@

advseo32

Now, it's clear that some thing is wrong with index, but i can't figured out
where is the problem

her is my code @
if( orientation == Qt::Vertical)
{
if( role == Qt::DecorationRole )
{
QModelIndexList indexes = m_selectionModel->selection().indexes();
QModelIndex index = m_selectionModel->selection().indexes().at(0);
if(m_selectionModel->isSelected(index))
return QPixmap("imgs/arrow.png");
}
}@

SGaist

Hi,

indexes might be empty, you don't check that case

advseo32

i have checked is the list isempty or no but the same problem

@if( role == Qt::DecorationRole )
{
QModelIndexList IndexsList = m_selectionModel->selection().indexes();
if(!IndexsList.isEmpty())
{
QModelIndex index = m_selectionModel->selection().indexes().at(0);
if(m_selectionModel->isSelected(index))
return QPixmap("imgs/square.png");
}
}
}@

advseo32

this is another code but, unfortunately also not working
@if( role == Qt::DecorationRole )
{
//i have used debugger and, the app crashed when execute the line below
bool indexListOk = m_selectionModel->selection().indexes().isEmpty() ;
if(!indexListOk)
{
QModelIndex index = m_selectionModel->selection().indexes().at(0);
if(m_selectionModel->isSelected(index))
return QPixmap("imgs/square.png");

}@

SGaist

Did you set m_selectionModel to something valid ?

If you follow the code from Andre carefully, you'll see that it checks first whether m_selectionModel is not NULL. Which also means that you must set it to NULL in your constructor.

advseo32

Oh! , i forgot to do this , thank's SGaist, andre, i will try to implement this
:)

SGaist

Always initializes all your pointers in the constructor either to something valid or NULL like in this case.

And check for NULL for all pointer variables that are initialized to NULL each time you'll be using these variables

advseo32

Yes, the probem caused by non initialisation of m_selectionModel pointer

but still i have a small a problem

when i select a row the icon show up, but when i leave the row (i can't get the icon disappear
@if(m_selectionModel)
{
QModelIndexList indexList = m_selectionModel->selection().indexes();
if(!indexList.isEmpty())
{
QModelIndex index = indexList.at(0);
if(index.isValid() )
return QPixmap("imgs/arrow.png");
}else{
return QSortFilterProxyModel::headerData(section,Qt::Vertical,Qt::DecorationRole);

            }

        }else{
            return QSortFilterProxyModel::headerData(section,Qt::Vertical,Qt::DecorationRole);
        }

@

JKSH

@Andre: The headerDataChanged() signal doesn't get emitted with this method, correct? Thus the view won't be notified to update the headers when it's meant to?

[quote author="advseo32" date="1375459821"]i'm not familiare with debugger[/quote]Take time to learn. It's a very valuable tool for programmers: http://qt-project.org/doc/qtcreator-2.8/creator-debugging.html

advseo32

[quote author="SGaist" date="1375475299"]Always initializes all your pointers in the constructor either to something valid or NULL like in this case.

And check for NULL for all pointer variables that are initialized to NULL each time you'll be using these variables[/quote]
Ok, i got it now :)

advseo32

bq.
[quote author="advseo32" date="1375459821"]i'm not familiare with debugger[/quote]Take time to learn. It's a very valuable tool for programmers: http://qt-project.org/doc/qtcreator-2.8/creator-debugging.html[/quote]

thanks JKSH, i will learn how i can use debugger

advseo32

the icon showed randomly in vertical header

her is my code @switch (role) {
case Qt::DecorationRole :
if(m_selectionModel)
{
QModelIndexList indexList = m_selectionModel->selection().indexes();
if(!indexList.isEmpty())
{
QModelIndex index = indexList.at(0);
if(index.isValid() )
{
for (int i=0;i<this->rowCount();++i)
{
if(i == index.row())
return QPixmap("imgs/arrow.png");
else
return QSortFilterProxyModel::headerData(section,Qt::Vertical,Qt::DecorationRole);
}
}
}else
return QSortFilterProxyModel::headerData(section,Qt::Vertical,Qt::DecorationRole);

        }else
            return QSortFilterProxyModel::headerData(section,Qt::Vertical,Qt::DecorationRole);


        break;
    default:
        QSortFilterProxyModel::headerData(section,orientation,role);
        break;
    }@

andre

[quote author="JKSH" date="1375487264"]@Andre: The headerDataChanged() signal doesn't get emitted with this method, correct? Thus the view won't be notified to update the headers when it's meant to?[/quote]

The point of my answer was not to provide a complete, ready to use solution, but give a pointer in the right direction. Emitting the changed signal was considered as an excersise for the reader, as was properly initializing the pointer to the selection model. The code I showed was just typed in quickly directly in the forum editor...

advseo32

i have emitted a signal to inform changes in vertical header but it won't
compile

and show me this error @E:\apprendreQt\gestionstock5\mytablemodel.cpp:54: erreur : passing 'const MytableModel' as 'this' argument of 'void QAbstractItemModel::headerDataChanged(Qt::Orientation, int, int)' discards qualifiers [-fpermissive]@

@if(m_selectionModel)
{

            QModelIndexList indexList = m_selectionModel->selection().indexes();
            if(!indexList.isEmpty())
            {
                QModelIndex index =   indexList.at(0);
                if(index.isValid() )
                {
                    emit headerDataChanged(Qt::Vertical,0,this->rowCount()-1);
                    return  QPixmap("imgs/arrow.png");

                }

            }else
                return QSortFilterProxyModel::headerData(section,Qt::Vertical,Qt::DecorationRole);
        }else
            return QSortFilterProxyModel::headerData(section,Qt::Vertical,Qt::DecorationRole);@

SGaist

Because you can't emit a signal from a const function

advseo32

[quote author="SGaist" date="1375558375"]Because you can't emit a signal from a const function[/quote]
I don't know about this, thank's, but really i haven't an idea on
where i will place this emit